ANS I Flashcards
What are the major cranial nerves carrying sympathetic fibers?
3,7,9,10
What type of receptor is innervated on chromaffin cells in the adrenal medulla by the preganglionic sympathetic fibers?
N2/Nn
What type of receptors are innervated by the SNS in sweat glands and what is the neurotransmitter used?
M3 and ACh
What is the receptor and neurotransmitter used by the SNS in the renal vasculature smooth muscle?
Dopamine and D1 receptors
What is the ratio of pre to postganglionic fibers in the SNS and PNS?
SNS 1:20
PNS 1:1
What are the 2 plexi in the enteric nervous system?
submucosa submucosal or Meisseners plexus circular muscle Myenteric or Aubachs plexus longitudinal muscle
What type of SNS and PNS fibers innervate the enteric nervous system?
Preganglionic PNS
Postganglionic SNS
How is acetylcholine produced?
Made from acetyl-CoA and choline by choline acetyltransferase
How is ACh removed from the synaptic cleft?
Acetylcholinesterase cleaves it to choline and acetate
How is NE synthesized
From Tyrosine -> DOPA -> dopamine -> NE
How is NE removed from the synaptic cleft?
diffusion and reuptake
Name 2 drugs the block the reuptake of NE?
Cocaine and TCAs
Names 2 drugs the promote release of NE?
Amphetamine and Tyramine
What type of proteins are the N1 and N2 receptors? which is a better drug target?
they are ACh gated non0selective ion channels. N1 is a better target.
What are the type of G protein each of the muscarinic receptors are coupled to and the cellular effects?
M1/M3/M5 are Gq receptors which activated PLC and create DAG and IP3 which increase calcium
M2/M4 are Gi which inhibit adenylate cyclase and decrease cAMP or activate K+ channel causing hyperpolarization
What are the type of G protein each of the Alpha and Beta adrenergic receptors are coupled to and what are their cellular effects?
alpha 1 - Gq receptors which activated PLC and create DAG and IP3 which increase calcium
alpha 2 - Gi which inhibit adenylate cyclase and decrease cAMP or activate K+ channel causing hyperpolarization
Beta 1/2/3 are Gs which activate adenylate cyclase and increase cAMP
What muscarinic receptors are involved in slowing the heart beat?
M2
What muscarinic receptors are involved in smoth muscle contraction? neuroregulation?
M3 sm contraction
M1 neuroreg
Match the appropriate adrenergic receptor with the following functions
sm muscle contraction
inhibition of neurotransmitter release
increase in force and rate of contraction of heart
sm muscle relaxation
lipolysis
alpha 1 sm muscle contraction
alpha 2 inhibition of neurotransmitter release
beta 1 increase in force and rate of contraction of heart
beta 2 sm muscle relaxation
beta 3 lipolysis
Describe how negative feedback is used at presynaptic terminals in the ANS.
Autorecptors and heteroreceptors act as negative feedback by damping the release of more neurotransmitter. These usually involve alpha 2 receptors and M2 receptors. This can allow crosstalk between the SNS and PNS
